Clamp for industrial trucks



April 20, 1954 R. E. THUROW 2,675,935

CLAMP FOR INDUSTRIAL TRUCKS Filed Nov. 30, 1950 s Sheqets-Sheet 1 FIG. I.

INVENTOR. ROBERT E. THUROW April 20, 1954 R. E. THUROW CLAMP FOR INDUSTRIAL TRUCKS 3 Sheets-Sheet 2 Filed Nov. 30, 1950 NQ NW A: @Ca as INVENTOR.

ROBERT E. THL'ROW ATTYS- April 20, 1954 R. E. THUROW 7 2,675,935

CLAMP FOR INDUSTRIAL TRucgs Filed Nov. 30, 1950 a Sheets-Sheet s INVENTOR. ROBERT E. THUROvz' ATTYS.

Patented Apr. 20, 1954 CLAMP FOR INDUSTRIAL TRUCKS Robert E. Thurow, Battle Creek, Mich., assignor to Clark Equipment Company,

Buchanan,

Mich., a corporation of Michigan Application November 30, 1950, Serial No. 198,405

My invention relates generally to load engaging means, and, more specifically, is directed to clamp means for use with industrial trucks.

It is an object of my present invention to provide an industrial truck with a clamp which is adapted to engage loads of irregular configuration.

It is another object of my present invention to provide an industrial truck with a clamp which is self-equalizing when engaging a load.

It is still another object ofmy present invention to provide an industrial truck with a clamp having three degrees of pivotal movement.

Now, in order to accomplish the aforementioned objects, I contemplate the provision of load engaging means comprising a pair of vertical forwardly extending clamp arm assemblies which are movable toward and away from each other. Each clamp arm assembly comprises a pair of vertically spaced arm members. rocker arm is pivotally mounted intermediate its ends to the lower arm member, about a substantially vertical aXis. The first rocker arm is also pivotally mounted to the lower arm mem- .to each pair of adjacent ends of the first and second rocker arms.

From the foregoin description, it will be realized that the clamp pads are adapted to pivot independently about the ends of the rocker arms, and the clamp pads are also adapted to pivot, as a unit, with the rocker arms about the-pivotal connections of the latter to the arm members;

The clamp pads are further adapted for pivotal movement about horizontal axes coinciding with the axes of the lower arm members. The clamp pads are thus capable of three degrees of pivotal movement, which may tak place either separately orsimultaneously.

Now, in order to acquaint those skilled in th art with the manner of constructing and usin the device of my present invention, I shall describe, I in connection with the accompanying drawings, a preferred embodiment of my invention;

In the drawings: Figure 1 is a side elevational'view of an industrial truck with which the load engaging 7 Claims., (Cl. 214-653) g 2 means of my present invention has been incorporated; V

Figure 2 is a front elevational view of the load engaging means of Figure 1;

Figure 3 is an enlarged side elevational view of one clamp assembly of the load engaging means of Figure 1; and

Figure 4 is a plan view of the clamp assembly of Figure 3.

Referring now to Fi ure 1, there is shown an industrial truck, indicated generally by the reference numeral H], which is provided with a pair of driving wheels I I adjacent the forward end thereof and a pair of steering wheels I2 adjacent'the rear end thereof. Mounted on the top of the frame of the truck I0 is a drivers seat I3. A steering column 14 is disposed forwardly of the driver's seat l3, and the steering column l4, adjacent its upper end, is provided with a hand steering wheel l5, operatively connected in a conventional manner to the rear steering wheels I2. A conventional mast I 3 is mounted at its lower end to the forward end of the truck [0. Mounted for vertical movement within the mast I6 is a load supporting carriage H, which carries a pair of vertically spaced transversely extending plate members l8 and l9. g

The load engaging mechanism of my present invention is indicated generally by the reference numeral 20, and comprises a clamp arm supporting and actuatin mechanism 2| and a pair of clamp arm assemblies 22, one disposed at each end of the clamp arm supporting'and actuating mechanism 2!. The supporting and actuating mechanism 2| is adapted to be secured to the upper transverse frame member "3 by hook-shaped, bracket members 23 and 24, which are disposed in engagement, respectively, with shown the clamp arm supportin and actuating mechanism 21 which comprises a pair of vertical transversely extending plate members 3| and 32. Disposed between the plate members 3| and 32 are a pair of horizontal opposed hydraulic piston and cylinder assemblies,v indicated generally by the reference numerals 33 and 34, which comprise, respectively, cylinders 35 and 36 and piston rods 31 and 38'. Each of the cylinders 35 and 36 has square collars 39 formed adjacent the ends thereof, which collars 39 are suitably secured to the plate members 3| and 32. Both ends of each of the cylinders and 3B are adaptd to be connected through hose lines (not shown) to fluid pressure developing means (not shown) carried by the truck ID.

A plurality of horizontal vertically spaced bar members til, 4|, 42, 33, 4, and 45 are disposed betweenthe plate-members 3! and32. 'Thelbar members "40, 4|, 44, and 45-are secured along their vertical edges to the plate members 3! and 32, while the bar member 52 is secured at its ends to the upper horizontal edges'orthe collar members 39 of the cylinder 35 and the bar member 43 is secured at its ends' -to the lower horizontal edges of the collar members 3t o'fth'e cylinder 35. As best shown in Figure 3, a plurality of horizontal substantially T-shaped channels 46, 41, 48, and 4d are formed, respectively, intermediate of the bar members 40 and 4|-,"4| and 42, 43 and 44, and 44 and 45.

Te'shape'd'sli'de members :50, .5 l 52 and :53 tare mounted, respectively, for sliding movementwithslide members 5| and '53 and .thepistonrod 38 are adapted :to project :outwardly of the-plate members 3! and-32 to the'1eft, a's viewed in'Figure 2. The T-shaped slide members-50 and. 52 and the pistonrod-E-"t are adapted toproject outwardly of the plate members 3| and 32 to the right,-as viewed in Figure 2.

One-'clamparm assembly 22 is secured to" the outer ends of 'the T-shaped-slide members 5| and 53 and the" piston rod 3'8 an'd oneclamp arm asvsembly 22 is secured tothe outer ends of the T-sh-aped slide members-.50v'and 52 and the" piston rod 31. In order to permit the clamparm assemblies 22 tobe moved closelytogethena plurality of horizontal-slots!!! are formedinthe forward plate member32 of the clamp arm supporting and actuatingmechanism-2 l. Since'each'of the clamp arm 1 assemblies .22 is identical in construction, with the exception thatcertain parts areireversed,

it isbelieved that a detailed description of enact the assemblies .22 willbe sufficientforrpurposesof the present disclosure.

As shown in Figure .3,- a vertically extending fabricated box-like framevmember 6| issecured to the forward vertical edges ot the T-shaped slide members 5.0 and 52, adjacent the ends thereof. Thelframe member 5| is also secured through afiange I H) to -the end of piston rod-r37.

formed thereon, to which is' suitably secured,. as by welding, a bearing 'plate member 65.

A sub stantially horizontally extending rocker arm member El is pivotally mounted, intermediate its ends, ton a substantially vertically extending pin member 8'8 carried bythexbearingplate'member 65. The :rooker. arm 6'! :isiprovided with 5a r'ib' l4.

. he rockerarm 61, 'adjacent its right i"8I1d, -aS viewedlin-Figure 3,'is formedwith'a slot- 69 into which projects the one end of a vertical pirr'member 70, secured at 'itsotherendiin the tubular armmemberfiil. Pivotal movement ofzthe rocker Y arm 6! about pin :68, is limited to .the extent of thamovement of :the pin :10 within the slot-69. Three hor-izontally spaced substantially vertically extending pin-members! l '12, and-l3 are secured .in the upper tubular arm member 62.

r the rocker arms 85 and 61. 'tally extending arm portions 98 and 99 are secured at their one ends in the rocker arm 61 for a purpose to be more fully described hereinafter.

As shown in Figures 3 and 4, the one end of a shaft 15 is fixed in the outer end of the upper tubular arm member 62. A pair of horizontal axially spaced sockets H and 18 are formed in the shaft 15, and an opening 19 is formed there "through andcountersunk at one end,

Disposed about the shaft 15 is a C-shaped bracket member which has a generally verticall extending pin member 8| secured in its uppernhorizontal leg. A bolt 32 is disposed through the opening19 in the shaft 75, and is threaded intoa threadedwopening formed in the bight por- "=tion-zofithe'..C+shaped bracket member 86. Spring members 83 and '84 are disposed, respectively, in the sockets 17 and I8, and at their outer ends engage the bight portion of the C-shaped bracket member '80 for normally biasing the latter away from the shaft 15. The head of the bolt 82 is "adapted \to engage the shoulder formed byvthe counters/inkingin the cop ening l 9, thereby limiting movement-of thelbracleet 80 relative to theshaft 15. VA .collarlmember H2 is fixed to theend of -shaft-15 andlimits axial movement of the bracket member '80 relative to the shaft 1.5.

Pivotally mounted on the pin member 8|, carried byvthe bracketmember .80, isa..rocker arm B5,.identical in shape tolthe rocker arm '67. The rocker'arm 85 is provided with a rib 9|. The rocker.arm"85, adjacent its rightend, as viewed .in Figures 3 and 4,.is formed with a. slot 86, into which slot 85 projects the one end of .a vertical pin member 31, suitably secured at its other end Pivotal movement of therocker arm 35 'about pin BI is limited to the extent of the movement of the pin 81 within the slot'86. Three horizontally spaced substantially vertically extending Vpin members 88, tltpandtt are secured at their one .ends in the rocker arm .85.

'The'tubular arm members "62 and'63 provide support'for'a 'pair of clamp pads, indicated gen- "erally'by'the reference numerals 92 and93. The clamp pads 92 'and93 comprise, respectively, tu- "bularframes'94 and H34, :to which are secured panels "95'and N35. The vertical'sides iof:the tu- 'bularfframes 94 and "i 84 "are, respectively, interconnected adjacent their upper ends by horizontal angdeflange members Stand '96 and adjacent "their'lower ends by horizontal angle flange members "97 and "91 'The' horizontal legs of the angle-flange membersflfi and9'l of the clamp padezare pivotally secured, respectively, to pin members 8B and of Generally horizonto the angle flange members 96 and's'l, adjacent the rightend thereof, as viewed inFigureB. The armportions98 and$39 are formed with slots I60 and HH, into which slots I00 and'lfll the aforementioned pin members 89 and""l2 project. Pivotal movement ofthe clamp pad 92 about pins'll and '88-is'limited to theextent of the movement oft-he pins l2'-and=89 within'slots I|l| and H30.

The-angle"flange members 96 'andt'l of the clamppads 93, intermediatetheir ends, arepivotally supported, respectively, on the pin members and '13, earrie'd bysthe rocker arms 85 and 1. (Suitablecoil springs I02 are secured at their one-ends to the angle flange members 96 and S1 of the clamp pad 93, and the springs Hi2 at their other ends are securedtothe l'lbS .JQI audlkof-therockerarmsflEand t7. Pivotal movement of the clamp padi'siihabout pins 13 andis limited by the springs I02. As described above, the clamp pads 92 and 93 are pivotally mounted to the rocker arms 85 and 61. Since the rocker arm 85 is pivotally mounted to the C-shaped bracket member 80, which, in turn, is

mounted on the shaft 15 for limited movement relative thereto, the clamp pads 92 and 93 are adapted for limited pivotal movement about a horizontal axis coinciding with the axis of the lower tubular arm member 63.

From the foregoing description, it will be realized that the load engaging mechanism of my present invention is particularly adapted for engaging loads of irregular shape. The clamp pads 92 and 93 are adapted to pivot independently, respectively, about generally vertically extending axes passing through pin members' and 88, and 13 and 90 fixed in the adjacent ends of the rocker arms 85 and B1. The clamp pads 92 and -93 are also adapted to pivot as a unit about a generally vertically extending axis passing through the pin members 68 and BI which sup-- port the rocker arms 51 and 85. The clamp pads "92 and 93 are further adapted for pivotal movebeen secured, the operator of the truck selectively I admits fluid under pressure to the closed ends of .the cylinders and 36 of the hydraulic piston and cylinder assemblies 33 and 34. The piston rods 31 and 38 are thus extended, causing the T-shaped slide members 5| and 53, together with the adjacent support arm assembly 22, and T-shaped slide members and 52, together with the adjacent support arm assembly 22, to move laterally away from the plate members 3| and 32. The truck I0 is then suitably maneuvered until a clamp arm assembly 22 is disposed on each side of the load to be engaged.

Fluid under pressure is then admitted to the forward ends of the cylinders 35 and 36 of the hydraulic piston and cylinder assemblies 33 and 34, while fluid is simultaneously bled from the closed ends of the cylinders 35 and 36. causes the piston rods 31 and 38 to be retracted.

This

Retraction of the piston rods 3'! and 38 causes the T-shaped slide members 50 and 52, together with the adjacent clamp arm assembly 22, and

T-shaped slide members 5| and 53, together with the adjacent clamp arm assembly 22, to be retracted toward the plate members SI and 32 until the pairsof clamp pads 92 and 33 engage the load. As aforedescribed, the pairs of clamp pads 92 and 93 are self-equalizing and thus will grip a load of irregular shape.

After the load has been gripped between the clamp arm assemblies 22, the load supporting carriage I1 is raised in the mast l6 until the load clears the ground. The truck It) may then be driven to the desired location where the load is to be deposited. The load supporting carriage I1 is then lowered in the mast l6 until the load engages the ground, after which fluid under pressure is selectively admitted to the closed ends of the cylinders 35 and 36, while fluid is bled from the forward ends of the cylinders 35 and 36. This causes the piston rods 31 and 38 to be extended which, as aforedescribed, effects spreading of the The truck It may then be backed away and is ready to engage another load.

While I have shown and described what I believe to be a preferred embodiment of my present invention, it will be understood that various modifications and rearrangements may be made therein without departing from the spirit and scope of my present invention.

I claim: v

1. For use with an industrial truck having a vertically movable load supporting carriage, load engaging means adapted to be mounted to the load supporting carriage for vertical movement therewith comprising, a pair of substantially vertical forwardly extending clamp arms movable toward and away from each other, a pair of clamp pads one carried by each of said clamp arms, and said clamp pads at their lower ends each being pivotally mounted about a horizontal axis relative to said clamp arms and being mounted at their upper ends for limited lateral movement relative to said clamp arms whereby said clamp pads are laterally movable at their upper ends while simultaneously being pivoted at their lower ends about said horizontal axes.

2. For use with an industrial truck having a vertically movable load supporting carriage; load engagingmeans adapted to be mounted to the load supporting carriage for vertical movement therewith comprising, a pair of substantially vertical forwardly extending clamp arms movable toward and away from each other, a pair of first rocker arms one pivotally mounted about horizontal and vertical axes to each of said clamp arms adjacent the lower ends thereof, a pair of second rocker arms one mounted for limited lateral movement and pivotal movement about a substantially vertical axis to each of said clamp arms adjacent the upper'ends thereof, clamp pads one pivotally mounted about a substantially vertical axis to each pair of adjacent ends of each pair of said first and second rocker arms, and said clamp pads being laterally movable at their upper ends with said second rocker arms while simultaneously being pivoted at their lower ends with said first rocker arms about said horizontal axes.

3. For use with an industrial truck having a vertically movable load supporting carriage, load engaging means adapted to be mounted to the load supporting carriage for vertical movement therewith comprising, a pair of substantially vertical forwardly extending clamp arms movable toward and away from each other, a pair of first rocker arms one pivotally mounted intermediate its ends about horizontal and vertical axes to each of. said clamp arms adjacent the lower ends thereof, a pair of second rocker arms one mounted intermediate its ends for limited lateral movement and pivotal movement about asubstantially vertical axis to each of said clamp arms adjacent the upper ends thereof, clamp pads one pivotally mounted about a substantially vertical axis to each pair of adjacent ends of each pair of said first and second rocker arms, and said clamp pads being laterally movable at their upper ends with said second rocker arms while simultaneously being pivoted at their lower ends with said first rocker arms about said horizontal axes.

4. For use with an industrial truck having a vertically movable load supporting carriage, load engaging means adapted to be mounted to the load supporting carriage for vertical movement therewith:comprising;za pair of vertical .torward'ly r'eictendingsclamp arm assemblies movable toward and away from each :other, each clamp arm assembly comprising .a pairsof vertically spaced arm :members, a first :rocker arm pivotally amounted intermediateitsends t the :lower arm member about asubst'antiallyvertical axis and an: axis coinciding with' the-axis of said lower arm member, a second :rocker arm :mounted intermediate its ends to the upper arm member-for .limited lateral movement and pivotal .movement about a substantially vertical axis, and clamp pads one pivotally:mountedsabout a-substantially vertical axis .to each, pair of adjacent ends of said first and second rocker arms.

:5. For use with an industrial truck :having a vertically movable load supporting carriage, load engaging meansadapted tobe mountedto the load supporting carriage for vertical. movement therewith comprising, a pair vof vertical forwardly extending clamp arm assemblies movable toward and away .from each other, each clamp arm .assembly comprising pair of vertically spaced arm members, a first .rocker .arm ,pivotally .mounted intermediate itsends to the .lowervarm member about a substantially vertical .axis and ,ang-axls coinciding with thelongitudinal axis of said lower ..arm.member, a second rocker arm mounted .intermediate its. ends to the upper arm .member for limited lateral movement and pivotal movement about .a substantially vertical :axis, clamp ,padsone pivotally mounted about a substantially verticaliaxis to each pair of. adjacent ends ofsaid .firstandsecond rocker arms, and said clamp pads being 'laterallymovable at their upper ends with said secondmockerarms while simultaneously being pivoted. at their lower ends, with said jfirstrocker arms, .about the ,longitu .dinal axes of saidlower arm members.

6. Foruse with anindustrial truck having a vertically movableload supporting carriage, load engaging means adapted to ,bemounted .to.the load supporting carriage for vertical movement therewith comprising, apair of substantially verticalrforward extending :clamp :arms ,movable toward and away from-eachother, a pair "of clamp jDadS'TOI'IB carried by eachof said clamp arms, means for pivotally mounting the lower ends ofeach of said clamp pads to said clamp .arms about a horizontal axis, and means for mounting the upper-ends of each of saidc-lamp ads to said clamp arms for limited lateral movementrelative thereto wherebysaid clamp pads are laterally movable at their upper ends while simultaneously being pivoted at their. lower ends about said horizontal axes.

'7. For use withan industrial truck having a vertically movable load supporting carriage, load engaging means adapted to be mounted to the load supporting carriage for vertical movement therewith comprising-a, pair of vertical forwardly extending clamp arm assemblies movable toward References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,807,360 Wehr May 26, 1931 2,226,789 Tupy Dec. 31, 1940 2,475,367 Avery July 5, 1949 2,497,118 Ferrario et al Feb. 14, 1950 2,536,151 Backofen et a1 Jan. 2, 1951 2,554,433 Warren May 22, 1951 2,561,896 Weiss July 24, 1951 2,571,550 'Ehmann Oct. 16, 1951 "2,604,220 "Frischmann July 22, 1952 

